// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_MESSAGE_CENTER_MESSAGE_CENTER_OBSERVER_H_
#define UI_MESSAGE_CENTER_MESSAGE_CENTER_OBSERVER_H_

#include <string>

#include "ui/message_center/message_center_export.h"
#include "ui/message_center/message_center_types.h"

namespace message_center {
class NotificationBlocker;

// An observer class for the change of notifications in the MessageCenter.
class MESSAGE_CENTER_EXPORT MessageCenterObserver {
public:
    virtual ~MessageCenterObserver() { }

    // Called when the notification associated with |notification_id| is added
    // to the notification_list.
    virtual void OnNotificationAdded(const std::string& notification_id) { }

    // Called when the notification associated with |notification_id| is removed
    // from the notification_list.
    virtual void OnNotificationRemoved(const std::string& notification_id,
        bool by_user) { }

    // Called when the contents of the notification associated with
    // |notification_id| is updated.
    virtual void OnNotificationUpdated(const std::string& notification_id) { }

    // Called when a click event happens on the notification associated with
    // |notification_id|.
    virtual void OnNotificationClicked(const std::string& notification_id) { }

    // Called when a click event happens on a button indexed by |button_index|
    // of the notification associated with |notification_id|.
    virtual void OnNotificationButtonClicked(const std::string& notification_id,
        int button_index) { }

    // Called when notification settings button is clicked.
    virtual void OnNotificationSettingsClicked() { }

    // Called when the notification associated with |notification_id| is actually
    // displayed.
    virtual void OnNotificationDisplayed(
        const std::string& notification_id,
        const DisplaySource source) { }

    // Called when the notification center is shown or hidden.
    virtual void OnCenterVisibilityChanged(Visibility visibility) { }

    // Called whenever the quiet mode changes as a result of user action or when
    // quiet mode expires.
    virtual void OnQuietModeChanged(bool in_quiet_mode) { }

    // Called when the blocking state of |blocker| is changed.
    virtual void OnBlockingStateChanged(NotificationBlocker* blocker) { }
};

} // namespace message_center

#endif // UI_MESSAGE_CENTER_MESSAGE_CENTER_OBSERVER_H_
